This is a thought-in-process post (Working Out Loud?) so feel free to provide me with some ideas, opinions and guidance.
Harold Jarche’s (@hjarche) Personal Knowledge Mastery learning programme has been asking us to think about any current or new media (medium) we use, or are due to start using. Then, to apply Marshall McLuhan’s tetrad of media effects, which was first seen in Laws of Media (1988).
To complete the tetrad the following questions need to be answered:
- What does the medium enhance (or Extend)?
- What does the medium make obsolete?
- What does the medium retrieve that had been obsolesced earlier?
- What does the medium reverse or flip into when pushed to extremes?
Our organisation is currently procuring a new Learning Management System, so I chose this for my first attempt:

I am looking at a localised, organisation-specific impact and I am sure that if I were to view this from a higher vantage point the content would change.
Do the entries in each diamond answer the questions asked? Is the Reverse a true opposite to the Extends? What might the bigger picture include in the diamonds?

Tetrading – Mastering my Personal Knowledge 4 by David Wallace was written in London, England and is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.